package chap5.reflection;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.*;

public class ReflectionTest {
    public static void main(String[] args)
    {
        // read class name from command line args or ues input
        String name;
        if(args.length > 0) name = args[0];
        else{
            Scanner in = new Scanner(System.in);
            System.out.println("Enter class name (e.g. java.util.Date): ");
            name = in.next();
        }

        try
        {
            // print class name and superclass name (if != Object)
            Class cl = Class.forName(name);
            Class supercl = cl.getSuperclass();
            String modifiers = Modifier.toString(cl.getModifiers());
            if(modifiers.length() > 0) System.out.print(modifiers + " ");
            System.out.print("class " + name);
            if(supercl != null && supercl != Object.class) System.out.print(" extends " + supercl.getName());

            System.out.print("\n{\n");
            printConstructors(cl);
            System.out.println();
            printMethods(cl);
            System.out.println();
            printFields(cl);
            System.out.println("}");
        }catch(ClassNotFoundException e){
            e.printStackTrace();
        }
        System.exit(0);
    }

    public static void printConstructors(Class cl)
    {
        Constructor[] constructors = cl.getDeclaredConstructors();

        for(Constructor c : constructors)
        {
            String name = c.getName();
            System.out.print("  ");
            String modifiers = Modifier.toString(c.getModifiers());
            if(modifiers.length() > 0) System.out.print(modifiers + " ");
            System.out.print(name + "(");

            // print parameter types
            Class[] paramTypes = c.getParameterTypes();
            for(int j = 0; j < paramTypes.length; j++)
            {
                if(j > 0) System.out.print(", ");
                System.out.print(paramTypes[j].getName());
            }
            System.out.println(");");
        }
    }

    public static void printMethods(Class cl)
    {
        Method[] methods = cl.getDeclaredMethods();

        for(Method m : methods)
        {
            Class retType = m.getReturnType();
            String name = m.getName();

            System.out.print("  ");
            // print modifiers, return type and method name
            String modifiers = Modifier.toString(m.getModifiers());
            if(modifiers.length() > 0) System.out.print(modifiers + " ");
            System.out.print(retType.getName() + " " + name + "(");

            // print parameter types
            Class[] paramTypes = m.getParameterTypes();
            for(int j = 0; j < paramTypes.length; j++)
            {
                if(j > 0) System.out.print(", ");
                System.out.print(paramTypes[j].getName());
            }
            System.out.println(");");
        }
    }

    public static void printFields(Class cl)
    {
        Field[] fields = cl.getDeclaredFields();

        for(Field f : fields)
        {
            Class type = f.getType();
            String name = f.getName();
            System.out.print("  ");
            String modifiers = Modifier.toString(f.getModifiers());
            if(modifiers.length() > 0) System.out.print(modifiers + " ");
            System.out.println(type.getName() + " " + name + "");
        }
    }
    
}
